The present invention relates to a locking device consisting of key and locking cylinder.
A locking device of this type is known from German OS 26 17 798 and is intended for use on diesel engines. The locking cylinder housing is strengthened on the head side into a cover cap covering the head plate of the cylinder core. The cap bottom thereof forms in the middle a passage opening for the insertion of a key. The passage opening extends over a range of angles of rotation and with its radially extending edges forms counter-stops which cooperate with a shoulder on the key shank. The construction of such a locking device is expensive from a production standpoint and accordingly increases the cost of production. Furthermore there is a large structural length in relation to the number of tumblers. In addition, the security value of such a locking device is less because of the unconcealed position of the stops.
A locking device, in particular for the actuation of electric microswitches on keyboards, telephones or the like, is furthermore known from German OS 2 856 006, in which an edge which lies at a different radius from the axis of rotation of the core is formed on the insertion end of the key shaft of every key by an additional notch. This edge controls an additional pin, is guided radially in the cylinder core, and the outward lying end of which, which extends beyond the cylinder core, enters into a groove in the locking cylinder housing which is open toward the cylinder core and the bottom surface of which consists of a plurality of partial sections arranged at different radial distances. They form stops which, depending on the key used, in combination with the stop pin limit the angle of rotation of the cylinder core. On the one hand, it has the disadvantage of being of expensive development. On the other hand, due to the additional pin arranged in front of the core pins, the length of the locking cylinder which can be used for variation of the locking is reduced.